Common broadcast channel low PAPR signaling in massive MIMO systems

Abstract

Methods and devices for common channel low PAPR signaling are disclosed having a power amplifier set configured to transmit broad-beam signals over a frequency band narrower than the available bandwidth and modulated with a low PAPR sequence. A second power amplifier set may be configured to transmit narrow-beam unicast signals.

What is claimed is: 
     
       1. A method of transmitting with a Multiple-Input Multiple-Output (MIMO) transmitter to User Equipment (UE) comprising:
 obtaining a low Peak-to-Average-Power-Ratio (PAPR) broadcast signal and a unicast signal; 
 amplifying the low PAPR broadcast signal at a first power amplifier of the MIMO transmitter; 
 amplifying the unicast signal at a second power amplifier of the MIMO transmitter; 
 transmitting the amplified unicast signal; 
 transmitting the amplified low PAPR broadcast signal in less than all time intervals in which the transmitter transmits; and 
 powering down the first power amplifier during time intervals in which the amplified low PAPR broadcast signal is not transmitted. 
 
     
     
       2. The method of  claim 1  wherein the low PAPR broadcast signal is obtained by applying a Zadoff-Chu sequence to a signal to be communicated wirelessly. 
     
     
       3. The method of  claim 1  wherein the low PAPR broadcast signal is obtained by applying a Golay complementary sequence to a signal to be communicated wirelessly. 
     
     
       4. The method of  claim 1  wherein the low PAPR broadcast signal comprises a Primary Synchronization Signal. 
     
     
       5. The method of  claim 4  wherein the Primary Synchronization Signal is transmitted over a central 62 subcarriers of an available bandwidth. 
     
     
       6. The method of  claim 1  wherein the low PAPR broadcast signal comprises a Secondary Synchronization Signal. 
     
     
       7. The method of  claim 6  wherein the Secondary Synchronization Signal is transmitted over a central 62 subcarriers of an available bandwidth. 
     
     
       8. The method of  claim 1  wherein the low PAPR broadcast signal comprises a Physical Broadcast Control Channel signal. 
     
     
       9. The method of  claim 8  wherein the Physical Broadcast Control Channel signal is transmitted over a central 72 subcarriers of an available bandwidth. 
     
     
       10. The method of  claim 8  wherein Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) is used to achieve a low PAPR in the low PAPR broadcast signal. 
     
     
       11. The method of  claim 10  further comprising using the DFT-S-OFDM with Space-Time block coding based Transmit Diversity (STTD). 
     
     
       12. The method of  claim 1  wherein the low PAPR broadcast signal comprises a Physical Downlink Control Channel signal. 
     
     
       13. The method of  claim 12  further comprising applying Orthogonal Frequency Division Multiplexing (OFDM) and Space-Frequency Transmit Diversity (SFTD) to the Physical Downlink Control Channel signal. 
     
     
       14. The method of  claim 13  further comprising applying QPSK with iterative clipping to the low PAPR broadcast signal to further reduce the PAPR of the low PAPR broadcast signal. 
     
     
       15. The method of  claim 1  wherein the low PAPR broadcast signal comprises a Physical Downlink Shared Channel signal. 
     
     
       16. The method of  claim 15  further comprising applying Orthogonal Frequency Division Multiplexing (OFDM) and Space-Frequency Transmit Diversity (SFTD) to the Physical Downlink Shared Channel signal. 
     
     
       17. The method of  claim 16  further comprising applying QPSK with iterative clipping to the low PAPR broadcast signal to further reduce the PAPR of the low PAPR broadcast signal. 
     
     
       18. The method of  claim 1  wherein the MIMO transmitter has a number of antennas greater than a number of the UE serviced by the transmitter. 
     
     
       19. The method of  claim 1  further comprising, during time intervals in which the amplified low PAPR broadcast signal is not transmitted, transmitting the unicast signal over a portion of a frequency spectrum in which the amplified low PAPR broadcast signal is transmitted when the amplified low PAPR broadcast signal is transmitted. 
     
     
       20. A Multiple-Input Multiple-Output (MIMO) transmitter for transmitting to User Equipment (UE), comprising:
 a first power amplifier configured to amplify a low Peak-to-Average-Power-Ratio (PAPR) broadcast signal to generate an amplified low PAPR broadcast signal; 
 a second power amplifier configured to amplify a unicast signal to generate an amplified unicast signal; 
 at least one antenna in communication with the first power amplifier and the second power amplifier, the at least one antenna configured to transmit the amplified low PAPR broadcast signal and transmit the amplified unicast signal; 
 a non-transitory memory storage comprising instructions; and 
 one or more processors in communication with the non-transitory memory storage, wherein the one or more processors execute the instructions to:
 cause the at least one antenna to transmit the amplified low PAPR broadcast signal in less than all time intervals in which the transmitter transmits; and 
 power down the first power amplifier during time intervals in which the amplified low PAPR broadcast signal is not transmitted. 
 
 
     
     
       21. The transmitter of  claim 20  wherein the low PAPR broadcast signal is obtained by applying a Zadoff-Chu sequence to a signal to be communicated wirelessly. 
     
     
       22. The transmitter of  claim 20  wherein the low PAPR broadcast signal is obtained by applying a Golay complementary sequence to a signal to be communicated wirelessly. 
     
     
       23. The transmitter of  claim 20  wherein the low PAPR broadcast signal comprises a Primary Synchronization Signal. 
     
     
       24. The transmitter of  claim 23  wherein the Primary Synchronization Signal is transmitted over a central 62 subcarriers of an available bandwidth. 
     
     
       25. The transmitter of  claim 20  wherein the low PAPR broadcast signal comprises a Secondary Synchronization Signal. 
     
     
       26. The transmitter of  claim 25  wherein the Secondary Synchronization Signal is transmitted over a central 62 subcarriers of an available bandwidth. 
     
     
       27. The transmitter of  claim 20  wherein the low PAPR broadcast signal comprises one of a Physical Broadcast Control Channel signal, Physical Downlink Control Channel signal, or Physical Downlink Shared Channel signal. 
     
     
       28. The transmitter of  claim 20  wherein the one or more processors further execute the instructions to apply Orthogonal Frequency Division Multiplexing (OFDM) and Space-Frequency Transmit Diversity (SFTD) to achieve a low PAPR in the low PAPR broadcast signal. 
     
     
       29. The transmitter of  claim 20  wherein the one or more processors further execute the instructions to apply QPSK with iterative clipping to achieve a low PAPR in the low PAPR broadcast signal. 
     
     
       30. The transmitter of  claim 20  wherein the transmitter has a number of antennas greater than a number of the UE serviced by the transmitter. 
     
     
       31. The transmitter of  claim 20  wherein the one or more processors further execute the instructions to, during time intervals in which the amplified low PAPR broadcast signal is not transmitted, transmit the unicast signal over a portion of a frequency spectrum in which the amplified low PAPR broadcast signal is transmitted when the amplified low PAPR broadcast signal is transmitted.